Ray Diagrams for Spherical Mirrors

Image Formation by Spherical Mirrors

• An extended object acts like multiple point sources, with rays emanating from each point.
• For clarity in ray diagrams, two rays originating from a point are commonly considered.
• Key rays for image localization include:
  • A ray parallel to the principal axis; for a concave mirror, it reflects through the principal focus (F). For a convex mirror, it diverges from F.

Characteristics of Images Formed by Concave Mirrors

• Image formation depends on the object's position relative to points: P (pole), F (focus), and C (center of curvature).
• Various outcomes for images based on object positioning:
  • At infinity: Image at focus F, highly diminished, real and inverted.
  • Beyond C: Image between F and C, diminished, real and inverted.
  • At C: Image at C, same size, real and inverted.
  • Between C and F: Image beyond C, enlarged, real and inverted.
  • At F: Image at infinity, highly enlarged, real and inverted.
  • Between P and F: Image behind the mirror, enlarged, virtual and erect.

Ray Diagrams for Image Formation by Lenses

• Spherical lenses also use ray diagrams to depict image formation.
• Important rays for representation in lenses:
  • A ray parallel to the principal axis, after passing through a convex lens, refracts through the focus on the opposite side.
  • In a concave lens, a parallel ray appears to diverge from the principal focus on the same side.

Characteristics of Images Formed by Concave Lenses

• A concave lens consistently yields a virtual, erect, and diminished image, regardless of the object's position.